1. Field of the Invention
The present invention relates to techniques for setting reference tones for monotone images.
2. Description of the Related Art
A variety of printing processes, such as color printing and monotone printing, can be performed using inkjet printers. Monotone printing includes “monochrome printing” in a narrow sense that reproduces images using only gray scales, and “monotone printing” in a narrow sense that reproduces images with the addition of a color tone or a tint aside from gray. Note that in the present specification, the words “monotone printing” is used to have a broad meaning that includes the narrow meaning of “monochrome printing” unless otherwise indicated. Technologies for printing monotone images are disclosed in, for example, JPH11-196285A, JP2002-331693A, JP2002-337323A, and JP2004-142423A.
A variety of color tones are used as monotone image tones, such as a neutral tone, a warm tone, a cool tone, and a sepia tone. However, there has not been so much devised a technique of setting desirable reference tones for monotone images.